Why do identical algorithms have different statistics?

I solved the problem for leetcode Here is my solution:

    public class Solution {
    public int NumberOfSteps(int num) {
        int steps = 0;
        while(num>0)
        {
            if(num % 2 == 0) num/=2;
            else num--;
            steps++;
        }
        return steps;
    }
}

The analysis produces the following statistics: Runtime: 46 ms Memory Usage: 25.1 MB

Here is the solution from Discuss And his stats: Runtime: 24 ms Memory Usage: 25.1 MB

Explain, please, what is the difference?